H. P. Grice, "Boethius on the multiplicity of 'esse'"

ESSE -- essence [from Latin esse, to be, a translation of Greek ousia or, more properly, to ti en einai, what it was for a thing to be, in an attempt to retain a relation with the term to be] Aristotle introduced the phrase to ti en einai. Instead of using the present tense esti (is), the Greek expression uses the philosophical imperfect en (was), which implies something remaining or eternal, although this implication is interpreted variably. Aristotle’s ontology begins with being and proceeds to what-it-is, to substance (primary being), and finally to essence, which is primary substance identical to form. The expression to ti en einai is derived from the formal structure of a question asking for a definition. Thus, essence is the ontological correlate and primary object of definition. Traditionally essence is taken to be a common nature shared by things of a certain kind, with the function of essence being to identify species membership or to place individuals into a species. But there are also many passages in Aristotle suggesting that essence and form as primary substance is particular. This gives rise to much controversy about how to understand the ontological status of essence. In general, essence is the property of a thing without which the thing could not be what it is. As essential property, it is distinguished from accidental properties. “What, then, you are by your very nature is your essence.” Aristotle, Metaphysics essential occurrence, see vacuous occurrence essential property, see accidental property essentialism Metaphysics, epistemology, logic, philosophy of language The doctrine that among the properties which a thing X possesses, we can distinguish between its essential properties and its accidental properties. According to this view, some of the properties of X form its essence, while the remaining properties are accidental. According to different kinds of essentialism, an essential property makes X the individual it is, the kind of thing it is, or a member of its kind. Essential properties are revealed by a real definition, although it is disputed whether there can be definitions either of individuals or of particular essences. Essentialism originated from Parmenides, Plato, and especially Aristotle, but has been in decline since the criticisms of British empiricism beginning in the seventeenth century. It was revived in the middle of the twentieth century and is represented in particular by Kripke. Contemporary essentialism claims that some properties of an object are essential to it and that so long as it existed the object could not fail to have them. If essence is inherent in things, then there are necessary truths about objects and their properties (necessity de re). Essentialism is focused on the relationship between essence and individual identity, as well as on the relationship between essence and natural kinds. It is closely related to the causal theory of reference and the theory of modality in terms of possible worlds. Various versions of anti-essentialism claim that the notion of essence is trivial or that we are never in a position to specify what properties of a thing are essential or accidental. Popper refers to essentialism as the view that the aim of science is to provide explanations in terms of things and properties that are not themselves susceptible of any further explanation. “Understood Platonistically, essentialism holds, at the very least, that some things have some of their properties essentially.” Slote, Metaphysics and Essence